1. Unix cat command
2. echo or printf command
3. vi text editor
4. emacs text editor
5. joe text editor
6. Any other console based text editor

Method #1: Creating a file using echo command

Open the Terminal and then type the following command to create a file called demo.txt, enter:

echo 'The only winning move is not to play.' > demo.txt

OR

printf 'The only winning move is not to play.\n' > demo.txt

OR create a file with two lines in demo-1.txt file:

printf 'The only winning move is not to play.\n Source: WarGames movie\n' > demo-1.txt

To examine the contents of the file you have just created is to type the following command at shell prompt:
cat demo.txt
cat demo-1.txt
Sample outputs:

Method #2: Creating a file using cat command

In this example, create a file named quotes.txt and enter one line of text in it, type the following at the shell prompt:

cat > quotes.txt

You need to press the [Enter] or [Return] key. Finally type the text:

There are some who question the relevance of space activities in a developing nation. To us, there is no ambiguity of purpose. 

Again, press the [Enter] or [Return] key. To stop and save file entry by typing Control+d on a line by itself i.e Press and hold down the Control key and type d. On your screen you will see as follows:
cat > quotes.txt
There are some who question the relevance of space activities in a developing nation.
To us, there is no ambiguity of purpose.
^D

OR

cat quotes.txt

Method #3: Create a text file using vi / vim text editor

vi / vim is a text editor. To create a file called text.txt, type:
$ vi bar.txt
Press i to insert new text. To save the file and leave vi, type ESC+:+x (press ESC key, type : followed by x and [enter] key).

How do I edit a file just created?

You need to use a text editor such as vi or emacs:
vi filename
Grab mastering the VI editor pdf file for more information on how to use a text editor (see below for link).

Further readings

• Learn more about vi here : Download mastering the VI editor pdf version.
• See man pages: cat(1),vi(1),vim(1),emacs(1),bash(1),ksh(1)